The invention arose during development efforts relating to a marine propulsion system having an engine in a closed or heat-retentive compartment causing problems of vapor lock, and or spewing.
After the engine is turned off, the temperature in the closed heat-retentive compartment in a marine propulsion system continues to rise. The fuel line and fuel pump are no longer cooled by the flow of incoming fuel from the cooler fuel tank. The stagnant fuel sitting in the fuel line and the fuel pump will begin to vaporize and or boil as the fuel line and fuel pump continue to heat up.
It is known in the prior art to provide insulation around the fuel lines to isolate the fuel from the heat.
The present invention addresses and solves the above noted fuel vaporization problem by providing a thermally inertial mass which is actively cooled during running of the engine, and which prevents vaporization of the fuel after the engine is turned off. A fuel line cooler in the compartment is in heat transfer relation with the fuel line and has an inlet communicating with the source of cooling water for the engine and has an outlet for discharging water. During running of the engine, water is circulated through the fuel line cooler. After the engine is turned off, the cooled water in the fuel line cooler provides the noted thermally inertial mass to prevent vaporization of the fuel.